No worries! When you do your follow up phone call notify the HR person who takes your phone call that you would like to update your information to include a phone number. If they ask why it was not listed tell them that you were in the middle of changing plans or just moved or something plausible...heck even tell the truth (they most likely will not ask)! This sort of thing happens and does not necessitate a deal breaker. What counts is that you follow up your resume, talk to a real person, and take action that shows responsibility. What's more is that in today's job market, employers prefer to send out emails anyway. Phone calls take time and an email takes less time.